U.S. patent number 7,881,769 [Application Number 10/408,156] was granted by the patent office on 2011-02-01 for method and system for mounting an mps sensor on a catheter.
This patent grant is currently assigned to MediGuide Ltd.. Invention is credited to Lior Sobe.
United States Patent |
7,881,769 |
Sobe |
February 1, 2011 |
Method and system for mounting an MPS sensor on a catheter
Abstract
Catheter for performing a medical operation on an organic lumen,
the catheter including an elongated member, a medical operational
element located at a distal end of the elongated member, an
electromagnetic field detector located at the distal end, and a
wiring for coupling the electromagnetic field detector with a
medical positioning system, wherein the medical positioning system
determines the position and orientation of the distal end.
Inventors: |
Sobe; Lior (Ra'anana,
IL) |
Assignee: |
MediGuide Ltd. (Haifa,
IL)
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Family
ID: |
32297426 |
Appl.
No.: |
10/408,156 |
Filed: |
April 7, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040097804 A1 |
May 20, 2004 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10298358 |
Nov 18, 2002 |
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Current U.S.
Class: |
600/424 |
Current CPC
Class: |
A61B
17/3207 (20130101); A61B 34/20 (20160201); A61B
2034/2072 (20160201); A61B 2034/2051 (20160201); A61M
25/104 (20130101); A61B 2017/00252 (20130101) |
Current International
Class: |
A61B
5/05 (20060101) |
Field of
Search: |
;600/424,427,429,117,409,407,114,118,300,317,479,481-488,460-463,410,100,160
;128/196 ;604/49-53,508-522 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
"PTCA with Stent"
http://www.bostonscientific.com/common.sub.--templates/articleDisplayTemp-
late.jhtml?task=tskProcedureOverview.jhtml§ionId=4&re1Id=2,63,64&proce-
dureId=94. cited by other .
"The Interventional Cardiac Catheterization Handbook" Morton J.
Kern, 3.sup.rd Edition, Mosby-Year Book Inc., 1999 pp. 17-43,
72-74, 80-101, 224-250 and 393-436. cited by other .
International Search Report; PCT Application No. PCT/IL03/00940
dated Feb. 28, 2006. cited by other.
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Primary Examiner: Casler; Brian
Assistant Examiner: Lamprecht; Joel M
Attorney, Agent or Firm: Dykema Gossett PLLC
Parent Case Text
This is a continuation of application Ser. No. 10/298,358, filed
Nov. 18, 2002 now abandoned. The prior applications is hereby
incorporated herein by reference, it its entirety.
Claims
The invention claimed is:
1. Catheter for performing a medical operation on an organic lumen,
the catheter comprising: an elongated member comprising
substantially flexible material; a medical operational element
located at a distal end of said elongated member; an
electromagnetic field detector located at said distal end, said
electromagnetic field detector operative to detect an
electromagnetic field generated by a medical positioning system
that is proximal of said elongated member distal end; and a wiring
for coupling said electromagnetic field detector with said medical
positioning system, said wiring operative to transmit a signal
respective of said detected electromagnetic field to said medical
positioning system, said wiring being separate and isolated from
said medical operational element and from said electromagnetic
field detector, said wiring embedded within substantially the
entirety of said elongated member between said medical positioning
system and said electromagnetic field detector such that said
wiring is positioned within the wall of said elongated member and
is surrounded, in said embedded portion, by said substantially
flexible material of said elongated member, wherein said medical
positioning system determines the position and orientation of said
distal end, relative to a reference coordinate system, according to
said transmitted signal, and wherein said elongated member has a
mechanical property of one of rigidity, elasticity, and plasticity,
and wherein said mechanical property of the part of said elongated
member between said medical positioning system and said
electromagnetic field detector where said wiring is embedded is
increased or decreased due to said mechanical property of said
wiring, irrespective of any modified mechanical property resulting
from said medical operational element or from said electromagnetic
field detector, such that the increase or decrease in said
mechanical property of the part of said elongated member between
said medical positioning system and said electromagnetic field
detector where said wiring is embedded enhances the maneuverability
of said catheter within said organic lumen throughout the stages
of: insertion of said catheter into the organic lumen, performance
of the medical operation with said medical operational element, and
removal of said catheter from the organic lumen.
2. Position and orientation determination system comprising: a
guiding catheter; a guiding catheter electromagnetic field detector
located at a guiding catheter distal end of said guiding catheter,
said guiding catheter electromagnetic field detector being coupled
with a medical positioning system; and at least one medical
catheter located within said guiding catheter, said at least one
medical catheter comprising: an elongated member comprising
substantially flexible material; a medical operational element
located at least one medical catheter distal end of a respective
one of said at least one medical catheter; a medical catheter
electromagnetic field detector located at said at least one medical
catheter distal end, said medical catheter electromagnetic field
detector operative to detect an electromagnetic field generated by
said medical positioning system that is proximal of said elongated
member distal end, and a wiring for coupling said medical catheter
electromagnetic field detector with said medical positioning
system, said wiring operative to transmit a signal respective of
said detected electromagnetic field to said medical positioning
system, said wiring being separate and isolated from said medical
operational element and from said electromagnetic field detector,
said wiring embedded within substantially the entirety of said
elongated member between said medical positioning system and said
electromagnetic field detector such that said wiring is positioned
within the wall of said elongated member and is surrounded, in said
embedded portion, by said substantially flexible material of said
elongated member, said elongated member having a mechanical
property of one of rigidity, elasticity, and plasticity, and
wherein said mechanical property of the part of said elongated
member between said medical positioning system and said
electromagnetic field detector where said wiring is embedded is
increased or decreased due to said mechanical property of said
wiring irrespective of any modified mechanical property resulting
from said medical operational element or from said electromagnetic
field detector, such that the increase or decrease in said
mechanical property of the part of said elongated member between
said medical positioning system and said electromagnetic field
detector where said wiring is embedded enhances the maneuverability
of said catheter within said organic lumen throughout the stages
of: insertion of said catheter into the organic lumen, performance
of the medical operation with said medical operational element, and
removal of said catheter from the organic lumen, wherein said
medical positioning system determines the position and orientation
of said at least one medical catheter distal end, relative to a
reference coordinate system, according to said transmitted signal,
and wherein said medical positioning system determines the position
and orientation of said guiding catheter distal end.
3. A catheter for performing a medical operation on an organic
lumen, comprising: an elongated member having proximal and distal
ends, said elongated member comprising substantially flexible
material; a medical operational element located at said distal end;
an electromagnetic field detector located at said distal end
configured to detect an electromagnetic field generated by a
medical positioning system and produce a signal respective of said
detected field, said medical positioning system being configured to
determine a position and orientation of said detector, relative to
a reference coordinate system, according to said signal; a wiring,
different from said medical operational element and said field
detector, coupled to said detector for transmitting said signal,
said wiring being embedded within and along at least a part of said
elongated member extending away from said distal end such that said
wiring is positioned within the wall of said elongated member and
is surrounded, in said embedded portion, by said substantially
flexible material of said elongated member said elongated member
having a mechanical property, and wherein said mechanical property
of said part of said elongated member where said wiring is embedded
is increased or decreased due to said wiring; wherein said wiring
along at least said part of said elongated member has a form
selected from the group comprising a straight form, a first spiral
form having a substantially constant pitch, a second spiral form
having a plurality of pitches, and a combination form having one or
more of the foregoing.
4. The catheter of claim 3 wherein said elongated member includes a
guidewire lumen for a guidewire to pass therethrough.
5. The catheter of claim 4 wherein said electromagnetic field
detector is located at a side of said guidewire lumen.
6. The catheter of claim 4 wherein said electromagnetic field
detector is in form of a coil which surrounds at least a portion of
said guidewire lumen.
7. The catheter of claim 4 wherein said electromagnetic field
detector is wound around a core comprising magnetically-permeable
material, said electromagnetic field detector being located
proximal to said guidewire lumen proximal end.
8. The catheter of claim 3 wherein said mechanical property is
selected from the group consisting of: pushability; trackability;
rigidity; elasticity; plasticity; flexibility; modulus of
elasticity; and coefficient of rigidity.
9. The catheter of claim 3 wherein said wiring takes said
combination form wherein at least a portion of said wiring is wound
in a spiral form having a pitch of at least one value, along the
length of said elongated member, and wherein at least another
portion of said wiring is substantially straight along the length
of said elongated member.
10. The catheter of claim 3 wherein said wiring is coated with an
electrically shielding coating.
11. The catheter of claim 3 wherein said wiring comprises one of
twisted pair conductors, coaxial conductors and triaxial
conductors.
12. The catheter of claim 3 wherein said wiring comprises first and
second conductors, said first electrical conductor being embedded
within said elongated member along a first path, said second
electrical conductor being embedded within said elongated member
along a second path, and wherein said first path and said second
path substantially lie on a plane, said plane substantially passing
through the longitudinal axis of said elongated member, and wherein
said first path and second path are substantially equally spaced
from said longitudinal axis.
13. The catheter of claim 3 wherein a first electrical conductor of
said wiring, a second electrical conductor of said wiring, and a
support element, are all embedded within said elongated member in
substantially straight lines, and wherein said first electrical
conductor, said second electrical conductor and said support
element substantially lie equally apart on a circle, said circle
being substantially concentric with it longitudinal axis in a
lateral cross section of said elongated member.
14. The catheter of claim 3 further comprising a radiopaque marker
embedded within said elongated member at said distal end.
15. The catheter of claim 3 wherein said medical operational
element is selected from the group consisting of: balloon; stent;
balloon expanding stent; laser; cryogenic fluid unit; electric
impulse unit; cutting balloon; rotational atherectomy unit;
directional atherectomy unit; transluminal extraction unit; coated
stent; drug delivery balloon; brachytherapy unit; valve; suturing
device; implant; biological marker; radiopaque marker; substance
delivery device; imaging device; diagnostic device; miniature
camera; infrared camera; optical coherence tomography; magnetic
resonance imaging; ultrasound; and sensor.
16. The catheter of claim 15 wherein said stent comprises a shape
memory alloy material.
17. The catheter of claim 3 wherein said catheter further comprises
a transmitter, said transmitter being coupled to a proximal end of
said wiring; and wherein said transmitter wirelessly couples said
electromagnetic field detector with said medical positioning
system.
18. The catheter of claim 3 further comprising a shielding covering
at least a portion of said electromagnetic field detector, wherein
said shielding is of such physical dimensions and properties, that
said shielding shields said electromagnetic field detector against
at least one electromagnetic field source.
19. A system for determining position and orientation, comprising:
a guiding catheter; a guiding catheter electromagnetic field
detector located at a guiding catheter distal end of said guiding
catheter, said guiding catheter electromagnetic field detector
being coupled with a medical positioning system; and at least one
medical catheter located within said guiding catheter, said at
least one medical catheter comprising: an elongated member having
medical catheter proximal and distal ends, said elongated member
comprising substantially flexible material; a medical operational
element located at said medical catheter distal end; an medical
catheter electromagnetic field detector located at said medical
catheter distal end configured to detect an electromagnetic field
generated by said medical positioning system and produce a signal
respective of said detected field, said medical positioning system
being configured to determine a position and orientation of said
medical catheter field detector, relative to a reference coordinate
system, according to said signal; a wiring, different from said
medical operational element and said medical catheter field
detector, coupled to said medical catheter field detector for
transmitting said signal, said wiring being embedded within and
along at least a part of said elongated member extending away from
said medical catheter distal end such that said wiring is
positioned within the wall of said elongated member and is
surrounded, in said embedded portion, by said substantially
flexible material of said elongated member, said elongated member
having a mechanical property, and wherein said mechanical property
of said part of said elongated member where said wiring is embedded
is increased or decreased due to said wiring; wherein said wiring
along at least said part of said elongated member takes a form
selected from the group comprising a straight form, a first spiral
form having a substantially constant pitch, a second spiral form
having a plurality of pitches and a combination form having one or
more of the foregoing.
20. The system of claim 19 wherein said guiding catheter
electromagnetic field detector is located within a wall of said
guiding catheter.
21. The system of claim 19 wherein said elongated member includes a
guidewire lumen for a guidewire to pass therethrough.
Description
FIELD OF THE DISCLOSED TECHNIQUE
The disclosed technique relates to medical devices in general, and
to methods and systems for determining the position and orientation
of a catheter, in particular.
BACKGROUND OF THE DISCLOSED TECHNIQUE
Medical operations on human or animal lumens, such as the vascular
system, ureter, urethra, brain vessels, coronary vessels, lumens of
the liver, kidney, lung, digestive system, and the like, can be
performed by employing a medical catheter. Such medical operations
include dilating a lumen by a balloon or a stent, implanting a
stent, delivering a pharmaceutical substance to the lumen,
performing coronary bypass, removing plaque from the intima of a
blood vessel, implanting a graft, and the like. Such a medical
catheter includes a lumen intervention element, such as a balloon,
stent, balloon expanding stent, substance delivery element, tissue
severing element, and the like, at the distal end thereof.
In some cases, the medical catheter also includes a radiopaque
material at the distal end, which serves as a marker for the
location of the distal end. In order to perform the medical
operation, usually a guiding catheter is initially inserted in the
lumen. Sometimes an auxiliary, large-diameter guidewire is inserted
prior to the guiding catheter for aiding it to enable manipulation
of the guiding catheter. Next, the large-diameter guidewire is
pulled out, another guidewire, with of smaller diameter, is
inserted in the guiding catheter and the small-diameter guidewire
is advanced to the desired location within the lumen, by
manipulating the tip of the small-diameter guidewire from outside
the body of the patient. The proximal end of the small-diameter
guidewire is inserted into the distal end of the medical catheter
and the medical catheter is advanced to the desired location, by
passing the medical catheter over the guidewire inside the guiding
catheter. The physician determines the position of the distal end
of the medical catheter, by viewing an image of the marker in an
imaging device, such as fluoroscope, X-ray table, and the like.
When the physician assures that the lumen intervention element is
located at the desired location, the physician performs the medical
task on the lumen.
U.S. Pat. No. 6,233,476 issued to Strommer et al., assigned to the
present assignee, and entitled "Medical Positioning System", is
directed to a medical positioning system (MPS) for determining the
position and orientation of a medical device within a living
tissue. The MPS includes a 3D electromagnetic field (EMF)
generator, a main sensor, an auxiliary sensor, a sensor interface,
a position and orientation processor, a superimposing processor, an
image interface, a 3D image database and a display unit.
The position and orientation processor is connected to the 3D EMF
generator, the sensor interface and to the superimposing processor.
The auxiliary sensor and the main sensor are connected to the
sensor interface. The image interface is connected to the
superimposing processor and to the 3D image database. The display
unit is connected to the superimposing processor. The main sensor
is located at the tip of the medical device. The auxiliary sensor
is located in the vicinity of the inspected tissue of the
patient.
The 3D image database includes a plurality of predetected images of
the inspected tissue of the patient. The auxiliary sensor
compensates for the movement of the patient. The 3D EMF generator
includes a plurality of electromagnetic coils that produce
electromagnetic fields in different directions and in different
magnitudes. Each of the main sensor and the auxiliary sensor
includes three electromagnetic coils. Each of the electromagnetic
coils of the main sensor and the auxiliary sensor detects an
electromagnetic field in a different direction. Each of the main
sensor and the auxiliary sensor produces a signal in response to
the electromagnetic field generated by the 3D EMF generator,
corresponding to the position and orientation of the main sensor
and the auxiliary sensor, respectively.
The position and orientation processor receives the signal from the
main sensor through the sensor interface and the position and
orientation processor determines the position and orientation of
the main sensor according to this signal. The superimposing
processor retrieves a predetected image of the inspected tissue
from the 3D image database, through the image interface. The
superimposing processor superimposes a representation of the tip of
the medical device on the retrieved image and produces a video
signal. The representation of the tip of the medical device
corresponds to the position and orientation of the tip of the
medical device relative to the inspected tissue. The display unit
produces a video image according to the video signal. U.S. Pat. No.
5,646,525 issued to Gilboa and entitled "Three Dimensional Tracking
System Employing a Rotating Field", provides a description of three
dimensional tracking system employed by the MPS for determining
position and orientation.
U.S. Pat. No. 6,179,811 issued to Fugoso, et al., and entitled
"Imbedded Marker and Flexible Guide Wire Shaft", is directed to a
balloon catheter which includes a marker band imbedded into a
guidewire shaft of the balloon catheter. The balloon catheter
includes a balloon, a shaft, a manifold, a guidewire shaft and a
plurality of marker bands. The guidewire shaft is located within
the shaft. The proximal end of the balloon is affixed to a distal
end of the shaft and the distal end of the balloon is bonded to a
distal end of the guidewire shaft. The manifold is located at a
proximal end of the shaft. The marker bands are imbedded into the
guidewire shaft at a region of the guidewire shaft below the
balloon. The marker bands can be viewed by fluoroscope
equipment.
U.S. Pat. No. 5,928,248 issued to Acker and entitled "Guided
Deployment of Stents.", is directed to an apparatus for applying a
stent in a tubular structure of a patient. The apparatus includes a
catheter, a hub, a pressure control device, a balloon, a stent, a
probe field transducer, a plurality of external field transducers,
a field transmitting and receiving device, a computer, an input
device and a cathode ray tube. The catheter includes a bore. The
hub is affixed to a proximal end of the catheter. The balloon is
mounted on a distal end of the catheter. The pressure control
device is connected to the balloon through the hub and the bore.
The stent is made of a shape memory alloy and is located on the
balloon.
The probe field transducer is located within the catheter, at a
distal end thereof. The external field transducers are located
outside of the patient (e.g., connected to the patient-supporting
bed). The field transmitting and receiving device is connected to
the external field transducers, the probe field transducer and to
the computer. The computer is connected to the cathode ray tube and
to the input device.
A user calibrates the field transmitting and receiving device in an
external field of reference, by employing the external field
transducers. The field transmitting and receiving device together
with the computer, determine the position and orientation of the
probe field transducer in the external field of reference. The user
views the position and orientation of a representation of the stent
which is located within a tubular structure of the patient, on the
cathode ray tube. When the user determines that the distal end is
located at the desired location within the tubular structure, the
user expands the stent by operating the pressure control device and
inflating the balloon, thereby positioning the stent at the desired
location.
U.S. Pat. No. 5,897,529 issued to Ponzi and entitled "Steerable
Deflectable Catheter Having Improved Flexibility", is directed to a
system for mapping a heart chamber and creating channels in the
heart tissue. The system includes a catheter, a computer, a monitor
and a pad containing coils. The catheter includes a catheter body,
a control handle, an optical fiber, a puller wire, a compression
coil, a tip electrode, a ring electrode, temperature sensing means,
an electromagnetic sensor and a circuit board. The control handle
is attached to a proximal end of the catheter body. A distal end of
each of the optical fiber, the puller wire and the compression
coil, is located at a distal end of the catheter body. A proximal
end of each of the optical fiber, the puller wire and the
compression coil, is located at a proximal end of the catheter
body.
The tip electrode, the ring electrode and the temperature means are
located at the distal end of the catheter body. The circuit board
is located within the control handle. The circuit board is attached
to the electromagnetic sensor and to the computer. The computer is
connected to the monitor and to the coils. The circuit board
prevents the system from being used twice, according to a signal
received from the electromagnetic sensor. The compression coil
provides flexibility to the catheter body.
The coils are located under the patient and generate a magnetic
field. The electromagnetic sensor generates a signal in response to
the generated magnetic field and the computer determines the
position of the electromagnetic sensor and thus the distal end of
the catheter body, by processing the signal. The tip electrode and
the ring electrode monitor the strength of the electrical signals
at a selected location. The temperature sensing means monitor the
temperature of the tip electrode.
The tip electrode and the ring electrode allow the user to map the
heart chamber. The user simultaneously maps the contours of the
heart chamber, the electrical activity of the heart and the
displacement of the catheter body, thereby identifying the location
of an ischemic tissue. The user then creates channels in the
ischemic tissue, via the optical fiber.
U.S. Pat. No. 5,830,222 issued to Makower and entitled "Device,
System and Method for Interstitial Transvascular Intervention", is
directed to a method for gaining percutaneous access to a diseased
vessel through an adjacent intact vessel. Using this method, it is
possible to bypass the diseased vessel, such as a coronary artery,
through the intact vessel, such as a cardiac vein. The diseased
vessel may include an occlusion that restricts the flow. A
guide-catheter is advanced through the vena cava into the coronary
sinus, within the right atrium of the heart. A transvascular
interstitial surgery (TVIS) guide catheter is inserted through the
guide-catheter and advanced through the cardiac vein over a first
guidewire, to a desired location adjacent the coronary artery.
The TVIS guide-catheter includes a balloon, a TVIS probe and either
or both of active orientation detection means and passive
orientation detection means. The TVIS probe is a rigid wire,
antenna, light guide or energy guide capable of being inserted in
tissue. The passive orientation detection means allow radiographic,
fluoroscopic, magnetic or sonographic detection of position and
orientation of the TVIS probe. The active orientation detection
means is a transmitter. A second guidewire is inserted into the
coronary artery adjacent the cardiac vein, wherein the second
guidewire includes a small receiver to receive a signal emitted by
the active orientation detection means. The second guidewire
further includes a wire bundle which is capable to return the
signal detected by the receiver, to an operator, thereby enabling
the operator to determine the position and location of the TVIS
probe.
When the orientation of the TVIS guide-catheter is assured, the
balloon is inflated against the wall of the cardiac vein, in order
to block the flow, stabilize the TVIS guide-catheter within the
cardiac vein and dilate the passageway. The TVIS probe, is then
advanced through the wall of the cardiac vein into the coronary
artery, thereby bypassing the diseased section of the coronary
artery.
U.S. Pat. No. 5,489,271 issued to Andersen and entitled
"Convertible Catheter", is directed to a percutaneous transluminal
coronary angioplasty (PTCA) device, which can be used in either the
rapid exchange mode or over-the-wire mode. The device includes a
catheter shaft and a hub assembly. The hub assembly is bonded to a
proximal end of the catheter shaft and the balloon is bonded to a
distal end of the catheter shaft. The hub assembly includes a
handle. The catheter shaft includes a guide element, a guidewire
lumen, a balloon inflation lumen, and a third lumen in which a
nitinol wire permanently resides.
In the rapid exchange mode, a first guidewire extends through the
distal end of the guidewire lumen and exits from the catheter
shaft, through a side port located distal of the guide element. In
this mode, a stylet is located within the guidewire lumen, wherein
the distal end of the stylet is proximal to the guide element and
the proximal end of the stylet is bonded to the handle. In
over-the-wire mode, the guide element is raised into general
alignment with the wall of the catheter shaft and the stylet and
the first guidewire are replaced by a second guidewire. The second
guidewire extends through the guidewire lumen, from the proximal
end of the device to the distal end thereof.
U.S. Pat. No. 6,035,856 issued to LaFontaine et al., and entitled
"Percutaneous Bypass with Branching Vessel", is directed to a
method for performing a bypass on a first occlusion of a branching
vessel of the aorta. A coronary artery which includes the first
occlusion, and a branching vessel branch out of the aorta. A
standard guide-catheter is advanced through the aorta up to the
ostium of the branching vessel. An occlusion forming device is
advanced through the guide-catheter into the branching vessel, to
produce a second occlusion in the branching vessel. The occlusion
device includes an elongate portion and a heated balloon.
The occlusion forming device is removed from the aorta through the
guide-catheter and a cutting device is advanced through the
guide-catheter proximal to the second occlusion. The cutting device
includes an elongate member, a steerable guidewire, a proximal
occlusion balloon, a distal balloon, a stent, a cutting blade, a
first piece of magnetic material and a transmitter. The cutting
blade is located distal to the distal balloon, the first piece of
the magnetic material is located between the cutting blade and the
distal balloon and the transmitter is located within the distal
balloon. The distal balloon is located within the stent. The
transmitter emits radio frequency signals.
The wall of the branching vessel is cut by employing the cutting
blade. The distal balloon is kept in the expanded position, in
order to occlude the branching vessel after the branching vessel
has been cut. The severed end of the branching vessel is steered
toward a region of the coronary artery distal to the first
occlusion, by maneuvering the steerable guidewire or by
manipulating the first piece of the magnetic material by a second
piece of magnetic material, wherein the second piece of magnetic
material is located outside the body of the patient.
The true position and the relative position of the transmitter and
thus the position of the severed end of the branching vessel, is
determined by employing a triangulation and coordinate mapping
system. The triangulation and coordinate mapping system includes
three reference electrodes which are located outside the body of
the patient. Two of the reference electrodes are located on
opposite sides of the heart and the third is located on the back.
The three reference electrodes are used to triangulate on the
transmitter.
When the severed end of the branching vessel is properly
positioned, an aperture is formed in the coronary artery distal to
the first occlusion, by employing the cutting blade. The severed
end of the branching vessel is inserted into the coronary artery
through the aperture and the stent is expanded by inflating the
distal balloon, thereby attaching the severed end of the branching
vessel to the lumen of the coronary artery.
SUMMARY OF THE DISCLOSED TECHNIQUE
It is an object of the disclosed technique to provide a novel
method and system for mounting an MPS sensor on a catheter, which
overcomes the disadvantages of the prior art.
In accordance with the disclosed technique, there is thus provided
a catheter for performing a medical operation on an organic lumen.
The catheter includes an elongated member, a medical operational
element located at a distal end of the elongated member, an
electromagnetic field detector located at the distal end, and a
wiring for coupling the electromagnetic field detector with a
medical positioning system. The medical positioning system
determines the position and orientation of the distal end.
In accordance with another aspect of the disclosed technique, there
is thus provided a position and orientation determination system.
The position and orientation system includes a guiding catheter,
and a guiding catheter electromagnetic field detector located at a
guiding catheter distal end of the guiding catheter. The guiding
catheter electromagnetic field detector is coupled with the medical
positioning system. The medical positioning system determines the
position and orientation of the guiding catheter distal end,
relative to a reference coordinate system.
In accordance with a further aspect of the disclosed technique,
there is thus provided a method for performing a medical operation
on an organic lumen. The method includes the procedures of
advancing a medical catheter to a desired location within the
organic lumen, and coupling an electromagnetic field detector
located at a distal end of the medical catheter, with a medical
positioning system, by a wiring.
The method further includes the procedures of generating an
electromagnetic field by the medical positioning system, detecting
the generated electromagnetic field by the electromagnetic field
detector, and transmitting a signal respective of the detected
electromagnetic field, to the medical positioning system, via the
wiring. The method further includes the procedures of determining
the position and orientation of the medical catheter distal end, by
the medical positioning system, according to the transmitted
signal, and performing the medical operation, by activating a
medical operational element located at the medical catheter distal
end.
In accordance with another aspect of the disclosed technique, there
is thus provided a position and orientation determination method.
The method includes the procedures of coupling an electromagnetic
field detector located at a distal end of a guiding catheter, with
a medical positioning system, and generating an electromagnetic
field by the medical positioning system.
The method further includes the procedures of detecting the
generated electromagnetic field, by the electromagnetic field
detector, and transmitting a signal respective of the detected
electromagnetic field, by the electromagnetic field detector. The
method further includes the procedure of determining the position
and orientation of the guiding catheter distal end relative to a
reference coordinate system, by the medical positioning system,
according to the transmitted signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosed technique will be understood and appreciated more
fully from the following detailed description taken in conjunction
with the drawings in which:
FIG. 1A is a schematic illustration of a system for determining the
position and orientation of an activation site of a medical
operational element of a medical catheter of the over-the-wire
type, constructed and operative in accordance with an embodiment of
the disclosed technique;
FIG. 1B is a schematic perspective illustration of a distal end of
the medical catheter of FIG. 1A;
FIG. 1C is a schematic illustration of a longitudinal cross section
of the distal end of one example of the medical catheter of FIG.
1A;
FIG. 1D is a schematic illustration of a longitudinal cross section
of the distal end of another example of the medical catheter of
FIG. 1A;
FIG. 2 is a schematic illustration of a system for determining the
position and orientation of an activation site of a medical
operational element of a medical catheter, constructed and
operative in accordance with another embodiment of the disclosed
technique;
FIG. 3 is a schematic illustration of a longitudinal cross section
of a distal end of a medical catheter, constructed and operative in
accordance with a further embodiment of the disclosed
technique;
FIG. 4 is a schematic illustration of a lateral cross section of
the wiring of a system for determining position and orientation,
such as shown in FIG. 1A, in a twisted pair formation, constructed
and operative in accordance with another embodiment of the
disclosed technique;
FIG. 5 is a schematic illustration of a lateral cross section of
the wiring of a system for determining position and orientation,
such as shown in FIG. 1A, in a coaxial formation, constructed and
operative in accordance with a further embodiment of the disclosed
technique;
FIG. 6 is a schematic illustration of a lateral cross section of
the wiring of a system for determining position and orientation,
such as shown in FIG. 1A, in a triaxial formation, constructed and
operative in accordance with another embodiment of the disclosed
technique;
FIG. 7A is a schematic illustration of a longitudinal cross section
of the distal end of the medical catheter of a system for
determining position and orientation, such as shown in FIG. 1A,
constructed and operative in accordance with a further embodiment
of the disclosed technique;
FIG. 7B is a lateral cross section of the medical catheter of FIG.
7A;
FIG. 8 is a schematic illustration of a lateral cross section of
the distal end of the medical catheter of a system for determining
position and orientation, such as shown in FIG. 1A, constructed and
operative in accordance with another embodiment of the disclosed
technique;
FIG. 9 is a schematic illustration of a longitudinal cross section
of the distal end of the medical catheter of a system for
determining position and orientation, such as shown in FIG. 1A,
constructed and operative in accordance with a further embodiment
of the disclosed technique;
FIG. 10 is a schematic illustration of a longitudinal cross section
of the distal end of the medical catheter of a system for
determining position and orientation, such as shown in FIG. 1A,
constructed and operative in accordance with another embodiment of
the disclosed technique;
FIG. 11 is a schematic illustration of a longitudinal cross section
of the distal end of a medical catheter of the rapid-exchange type,
constructed and operative in accordance with a further embodiment
of the disclosed technique;
FIG. 12 is a schematic illustration of a longitudinal cross section
of the distal end of a medical catheter of the rapid-exchange type,
constructed and operative in accordance with another embodiment of
the disclosed technique;
FIG. 13 is a schematic illustration of a system for determining the
relative positions and orientations of a plurality of medical
catheters, constructed and operative in accordance with a further
embodiment of the disclosed technique;
FIG. 14 is a schematic illustration of a system for determining the
position and orientation of a guiding catheter, constructed and
operative in accordance with another embodiment of the disclosed
technique; and
FIG. 15 is a schematic illustration of a method for operating the
system of FIG. 1A, operative in accordance with a further
embodiment of the disclosed technique.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The disclosed technique overcomes the disadvantages of the prior
art by providing a medical catheter which includes a medical
operational element, and an electromagnetic field detector located
in proximity of the activation site of the medical operational
element. The activation site of the medical operational element is
located at a distal end of the medical catheter. The
electromagnetic field detector is coupled with a medical
positioning system by a wiring. The wiring may be constructed to
improve the pushability and traceability of the medical catheter
(i.e., the possibility of the medical catheter to follow the path
within a human or animal lumen, when pushed through the lumen). A
transmitter of the medical positioning system generates an
electromagnetic field and the electromagnetic field detector
detects the generated electromagnetic field. The electromagnetic
field detector sends a signal respective of the detected
electromagnetic field to the medical positioning system and the
medical positioning system determines the position and orientation
of the electromagnetic field detector, and hence the activation
site, according to the received signal. It is noted that the term
"lumen" refers to an organic tubular structure of the human patient
or the operated animal. This lumen is different than the "guidewire
lumen" which is a channel in the medical catheter used for passing
a guidewire there through.
Reference is now made to FIGS. 1A, 1B, 1C and 1D. FIG. 1A is a
schematic illustration of a system for determining the position and
orientation of an activation site of a medical operational element
of a medical catheter of the over-the-wire type, generally
referenced 100, constructed and operative in accordance with an
embodiment of the disclosed technique. FIG. 1B is a schematic
perspective illustration of a distal end 144 of the medical
catheter of FIG. 1A. FIG. 1C is a schematic illustration of a
longitudinal cross section of the distal end of one example of the
medical catheter of FIG. 1A. FIG. 1D is a schematic illustration of
a longitudinal cross section of the distal end of another example
of the medical catheter of FIG. 1A.
System 100 includes a medical catheter 102, a guidewire 104 and a
medical positioning system (MPS) 106. Medical catheter 102 includes
an elongated member 108, a manifold 110, a medical operational
element 112 and an electromagnetic field detector 114. The medical
operational element can include a lumen intervention element, a
lumen diagnostic element, a lumen imaging element, and the like.
Elongated member 108 is made of a substantially flexible material,
such as poly ether ether ketone (PEEK), polyethylene (PE), nylon,
polyurethane, polyvinyl chloride (PVC), polyethylene terephthalate
(PET), Pebax.RTM., polyimide, metal (either solid or coiled), such
as nitinol, stainless steel, hypotube (i.e., an ultra low diameter
and ultra thin walled tube), and the like. Elongated member 108 has
a substantially circular cross section and includes a guidewire
lumen 116. Manifold 110 is located at a proximal end of medical
catheter 102 and medical operational element 112 is located at a
distal end of medical catheter 102.
Medical operational element 112 is an element for performing
medical operations in the lumen, such as modifying the
characteristics of the lumen, or diagnosing the lumen, such as
obtaining an image of the lumen. The characteristics of the lumen
can be modified by performing a medical procedure thereon, such as
percutaneous transluminal coronary angioplasty (PTCA), percutaneous
transluminal angioplasty (PTA), vascularizing the lumen, severing a
portion of the lumen or a plaque there within (e.g., atherectomy),
providing a suture to the lumen, increasing the inner diameter of
the lumen (e.g., by a balloon, a self expanding stent, a stent made
of a shape memory alloy (SMA), or a balloon expanding stent) and
maintaining the increased diameter by implanting a stent.
Medical operational element 112 can be further used to deliver
substances to the lumen. For example, medical operational element
112 can be used to deliver a pharmaceutical substance to a selected
site within the lumen, such as for inhibiting angiogenesis of
cancerous cells, inhibiting metastasis, stimulating local hormonal
activity of tissue cells and stimulating healing following a
trauma. Medical operational element 112 can be further used for
killing selected cells (either cancerous or non-cancerous) at the
activation site of medical operational element 112 or in the
vicinity thereof, by irradiating the cells with a radioactive
substance, electric current, laser, or subjecting the cells to a
cryogenic fluid, and the like. Medical operational element 112 can
be further include, or be used for deployment of, a device within
the lumen. Such a device can be for example, a valve (e.g., mitral
valve, sphincter), suturing device, implant, biological marker,
radiopaque marker, substance delivery device, imaging device,
diagnostic device, miniature camera, infrared camera, optical
coherence tomography (OCT), magnetic resonance imaging (MRI),
ultrasound, sensor, such as pressure sensor, temperature sensor, pH
sensor, and the like. The sensor can be in form of a passive
ultrasonic transducer, which transmits signals bearing the value of
the detected parameter (pressure, temperature, pH etc.), in
response to an ultrasonic wave directed from an external source
toward the sensor. Medical operational element 112 can also be used
to perform a valvuloplasty operation (i.e., repair of an organic or
an artificial valve). The lumen can be a portion of the vascular
system, ureter, urethra, brain vessels, coronary vessels, vas
deferens, lumens of the liver, kidney, lung (e.g., trachea and
bronchus), digestive system, gal bladder, prostate gland,
urogenital system, and the like. The lumen can be in the body of a
human being as well as an animal.
Medical operational element 112 can be an expansion unit such as a
balloon, stent, balloon expanding stent, an ablation unit such as
laser, cryogenic fluid unit, electric impulse unit, cutting
balloon, rotational atherectomy unit (i.e., rotablator),
directional atherectomy unit, transluminal extraction unit, a
substance delivery unit such as coated stent, drug delivery
balloon, brachytherapy unit, and the like.
The balloon expanding stent unit includes a stent which is located
around a balloon. When the balloon is inflated, the stent expands.
The cutting balloon unit includes a balloon having a plurality of
blades on the periphery thereof, along the longitudinal axis of the
elongated member. The cryogenic fluid unit includes a fluid
delivery lumen through which a fluid at a substantially low
temperature is delivered to a desired site of the lumen. The
electric impulse unit includes two electrical conductors. An
electrical arc generated at the tip of the electrical conductors
ablates the desired site of the lumen.
The rotablator includes a diamond coated tip which is coupled with
an external motor via a flexible shaft. The flexible shaft rotates
the diamond coated tip at a substantially high speed, wherein the
diamond coated tip grinds calcified plaque which is formed on the
inner wall of the lumen. The ground material enters the
circulation.
The directional atherectomy unit includes a cutter and a balloon.
The cutter is coupled with an external motor via a flexible shaft.
The balloon pushes the cutter toward the sidewall opposite to the
balloon, thereby allowing the cutter to cut the calcified plaque.
The calcified particles are pumped out through the medical
catheter. The transluminal extraction unit includes a cutter which
is coupled with an external motor via a flexible shaft. The motor
rotates the cutter, wherein the cutter cuts the calcified plaque
and the calcified particles are pumped out through the medical
catheter.
The coated stent is coated with a pharmaceutical substance, wherein
the substance is released into a desired region of the lumen, when
the coated stent is installed in the lumen. The drug delivery
balloon is a balloon which is coupled to a source of a
pharmaceutical substance, via a drug delivery lumen. The
pharmaceutical substance exits the balloon through a plurality of
micropores. The brachytherapy unit includes a substance delivery
lumen, through which radioactive palettes are delivered to a
desired site within the lumen. The radioactive palettes remain at
the desired site for a prescribed time and then are scavenged out
through the substance delivery lumen. Thus, a prescribed dose of
radiation is delivered to the desired site of the lumen.
In the example set forth in FIG. 1A, medical catheter 102 is a
balloon type catheter. Hence, medical operational element 112
includes a tube portion 118 and a balloon portion 120. Each of tube
portion 118 and balloon portion 120 is made of a substantially thin
and flexible material, such as polyamide (e.g., nylon), and the
like. Balloon portion 120 can be made either of a compliant
material, semi-complaint material, or a non-compliant material. A
compliant balloon continuously expands as higher pressures are
applied thereto. A non-compliant balloon expands up to a
predetermined diameter which is designed therein, and ceases to
expand above this predetermined diameter, even if the applied
pressure continues to rise. The expansion rate of a semi-compliant
balloon drops as the pressure rises. Balloon portion 120 is located
at a distal end of tube portion 118. A proximal end of tube portion
118 is coupled with a pressurized fluid source (not shown), via
manifold 110 and a circumferential fluid lumen 140. Circumferential
fluid lumen 140 runs along the entire length of medical catheter
102. The pressurized fluid source can be an ampoule such as a
syringe, and the like, which contains a biocompatible fluid. The
pressurized fluid source can be provided with a sensor to detect a
property of the fluid, such as pressure, temperature, pH, and the
like.
A distal end 122 of balloon portion 120 is coupled with an outer
wall (not shown) of elongated member 108, by methods known in the
art, such as by an adhesive, ultrasonic welding, heat bonding, by
applying infrared radiation, radio frequency (RF) radiation, laser,
ultraviolet (UV) radiation, and the like. The circumference of
balloon portion 120 is larger than that of tube portion 118. In an
uninflated state, balloon portion 120 folds around elongated member
108. When fluid flows under pressure from the pressurized fluid
source into tube portion 118, balloon portion 120 unfolds and
expands. When the pressure fluid source is unpressurized or the
fluid is withdrawn from tube portion 118, the interstitial fluid in
the lumen forces balloon portion 120 to fold around elongated
member 108.
Electromagnetic field detector 114 is an electric conductor formed
into a coil. Electromagnetic field detector 114 is embedded within
elongated member 108, such that guidewire lumen 116 passes through
the winding of electromagnetic field detector 114. Alternatively,
the electromagnetic field detector can be sufficiently small to be
entirely embedded within a lateral portion of the wall of the
elongated member, adjacent to guidewire lumen 116. In the example
set forth in FIGS. 1A, 1B and 1C, electromagnetic field detector
114 is embedded within elongated member 108, in such a location
that when balloon portion 120 expands, balloon portion 120
encompasses electromagnetic field detector 114. However, it is
noted that electromagnetic field detector 114 can be located either
distal or proximal to balloon portion 120. Furthermore,
electromagnetic field detector 114 can be made of a radiopaque
material or coated with such a material, thereby being detectable
by an imaging device, such as radiographic, fluoroscopic, magnetic,
sonographic device, and the like.
With reference to FIG. 1A, MPS 106 includes a detector interface
124, a processor 126, a display 130, an image database 132 and a
transmitter 134. MPS 106 is located outside the body of a patient
(not shown). Processor 126 is coupled with detector interface 124,
display 130, image database 132 and with transmitter 134. Image
database 132 includes a plurality of images of a lumen (not shown)
of the patient, wherein each image is associated with a set of
position and orientation coordinates, in a reference coordinate
system.
Two ends (not shown) of electromagnetic field detector 114 are
coupled with two distal ends (not shown) of a wiring 136, via a
flexible printed circuit board (PCB) 138. However, it is noted that
the two ends of electromagnetic field detector 114 can be coupled
with the two distal ends of wiring 136, directly, (e.g., by
soldering or conductive adhesion) in which case flexible PCB 138
can be disposed of. Proximal ends (not shown) of wiring 136 are
coupled with detector interface 124. For a more elaborate
description of an MPS, confer U.S. Pat. No. 6,233,476 mentioned
above.
Wiring 136 is made of an electric conductor, such as copper, gold,
silver, and the like. Wiring 136 is spirally embedded within
elongated member 108, such that guidewire lumen 116 is surrounded
by wiring 136. It is noted that the term "spiral" includes, inter
alia, helical forms. The pitch of wiring 136 is referenced by
P.sub.1. Wiring 136 is spirally embedded within elongated member
108 at pitch P.sub.1, in a section (not shown) of elongated member
108 which starts from the two distal ends of electromagnetic field
detector 114 and ends at manifold 110. Alternatively, wiring 136 is
spirally embedded within the section of elongated member 108, at a
plurality of different pitches. Further alternatively, a portion of
wiring 136 proximal to electromagnetic field detector 114 is
spirally embedded within elongated member 108 at pitch P.sub.1, and
the rest of wiring 136 is embedded within elongated member 108
along a substantially straight line. Alternatively, at least one
portion of wiring 136 is spirally embedded within elongated member
108 and at least another portion of wiring 136 is embedded within
elongated member 108, along a substantially straight line. With
reference to FIG. 1D, a wiring 142 is embedded within elongated
member 108, along a substantially straight line.
According to one aspect of the invention the spiral winding of
wiring 136 modifies certain mechanical properties of elongated
member 108, such as improving the pushability and trackability of
medical catheter 102 within the lumen of the patient (i.e.,
reducing the tendency of medical catheter 102 to buckle when pushed
within the lumen and increasing the ability of the medical catheter
to follow the vessel path), increasing the elasticity of elongated
member 108 (i.e., increasing the tendency of elongated member 108
to return to the original shape, after being deformed), increasing
the modulus of elasticity of elongated member 108 (i.e., increasing
the mechanical stress in either compression or tension, which is
required to deform elongated member 108 by a certain amount),
increasing the coefficient of rigidity of elongated member 108
(i.e., increasing the mechanical shear stress which is required to
twist elongated member 108 by a certain angle), affecting the
flexibility or resilience of elongated member 108, and the like. It
is further noted that the mechanical properties of wiring 136, also
modifies the mechanical properties of elongated member 108. Wiring
136 can be coated with a coating that provides electrical
insulation, or electrical shielding, as well as mechanical
protection to wiring 136.
Following is a description of operation of system 100. Initially,
the user (usually a physician) inserts a guiding catheter (not
shown) into the lumen, such that a distal end of the guiding
catheter reaches a desired location within the lumen. The physician
can view an image of the guiding catheter by employing an imaging
device, such as radiographic, fluoroscopic, magnetic, sonographic
device, and the like. The physician inserts guidewire 104 in the
guiding catheter and maneuvers a distal end (not shown) of
guidewire 104 past the guiding catheter through the lumen, by
observing an image of guidewire 104 in an imaging device, such as
radiographic, fluoroscopic, magnetic, sonographic device, and the
like Guidewire 104 is a "small-diameter" guidewire, referred to in
the Background of the Disclosed Technique, hereinabove. The
physician, then inserts a proximal end (not shown) of guidewire 104
in the distal end of medical catheter 102, and passes medical
catheter 102 over guidewire 104, into the lumen, such that the
proximal end of guidewire 104 usually exits a proximal end (not
shown) of medical catheter 102. This mode of operation is known in
the art as "over-the-wire". Alternatively, no guidewire is employed
in the procedure, in which case the physician passes the medical
catheter out through the distal end of the guiding catheter, until
the distal end of the medical catheter reaches a selected location
within the lumen. Transmitter 134 produces a rotating magnetic and
electric field of fixed strength, orientation and frequency.
Electromagnetic field detector 114 produces a signal according to
the position and orientation thereof, relative to transmitter 134
and electromagnetic field detector 114 provides this signal to
detector interface 124, via wiring 136. Processor 126 receives the
signal via detector interface 124 and processor 126 determines the
position and orientation of electromagnetic field detector 114
relative to the reference coordinate system, according to the
received signal.
Processor 126 retrieves an image of the lumen from image database
132 and superimposes a representation of medical operational
element 112 on the retrieved image, according to the determined
position and orientation. Processor 126 produces a video signal
respective of the superimposed image to display 130 and display 130
produces the representation of medical operational element 112,
superimposed on the image of the lumen. When the physician is
assured that medical operational element 112 is located at the
desired site within the lumen, by viewing the superimposed image on
display 130, the physician can commence the medical operation on
the lumen.
Various electronic devices which are present in the operation room,
may emit electromagnetic radiation which may interfere with the
signal which the electromagnetic field detector transmits to the
MPS, via the wiring. In this case, necessary hardware or software
has to be incorporated with the system, in order to reduce the
effect of these interfering signals.
For example, at least a portion of the electromagnetic field
detector can be covered with a shielding of such thickness and
material (e.g., a conductive foil, a wire mesh), to selectively
cancel out these interfering signals, while allowing the signal
from the transmitter of the MPS, to reach the electromagnetic field
detector. This electrical shielding of the wiring acts as a Faraday
cage within a predetermined range of frequencies.
Reference is now to FIG. 2, which is a schematic illustration of a
system for determining the position and orientation of an
activation site of a medical operational element of a medical
catheter, generally referenced 146, constructed and operative in
accordance with another embodiment of the disclosed technique.
System 146 includes a medical catheter 148 and an MPS 150. FIG. 2
illustrates the distal portion of medical catheter 148, which is
typically about 20 cm long.
Medical catheter 148 includes an elongated member 152, a medical
operational element 154, an electromagnetic field detector 156, a
wiring 158 and a transmitter 160. Elongated member 152 includes a
guidewire lumen 162. MPS 150 includes a processor 164, a
transmitter 166, an image database 168, a display 170, a detector
interface 172 and a receiver 174.
Wiring 158 is similar to wiring 136 (FIG. 1B), as described herein
above and is embedded within elongated member 152. Medical
operational element 154 and electromagnetic field detector 156 are
located at a distal end 176 of medical catheter 148.
Electromagnetic field detector 156 is embedded within elongated
member 152, and encompasses guidewire lumen 162. Transmitter 160 is
embedded within elongated member 152 and located proximal to distal
end 176. Alternatively, the transmitter can be located at a
manifold similar to manifold 110 (FIG. 1A) or anywhere along
elongated member 152 or external thereto. One end of wiring 158 is
coupled with electromagnetic field detector 156 and the other end
thereof is coupled with transmitter 160. The length of wiring 158
is much shorter than that of elongated member 152, such that wiring
158 occupies a relatively short section of the distal portion of
elongated member 152 (usually about 20 cm).
Processor 164 is coupled with transmitter 166, image database 168,
display 170 and with detector interface 172. Receiver 174 is
coupled with detector interface 172. Transmitter 166 transmits an
electromagnetic wave which is received by electromagnetic field
detector 156 and electromagnetic field detector 156 sends a signal
respective of the position and orientation of distal end 176 to
transmitter 160, via wiring 158. Transmitter 160 transmits this
signal to receiver 174 and processor 164 determines the position
and orientation of distal end 176, according to a signal received
from detector interface 172.
It is noted that wiring 158 modifies the mechanical properties of
the distal portion of elongated member 152, as described herein
above in connection with FIG. 1B, such as pushability and
trackability. Alternatively, the electromagnetic field detector can
be located external to the elongated member (as described herein
below in connection with FIG. 3). Further alternatively, the wiring
can be wound around the elongated member. Further alternatively,
the transmitter can be located external to the elongated member. It
is further noted that medical catheter 148 can be of over-the-wire
type, as well as rapid exchange type.
Reference is now made to FIG. 3, which is a schematic illustration
of a longitudinal cross section of a distal end of a medical
catheter, generally referenced 180, constructed and operative in
accordance with a further embodiment of the disclosed technique.
Medical catheter 180 includes an elongated member 182, a medical
operational element 184, an electromagnetic field detector 186, a
marker 188 and a wiring 190. A guidewire 192 can pass through a
guidewire lumen 194 within elongated member 182.
Elongated member 182 and medical operational element 184 are
similar to elongated member 108 (FIG. 1A) and medical operational
element 112, respectively. Electromagnetic field detector 186 is
made of a conductor which is wound around an outer wall 196 of
elongated member 182, at an activation site of medical operational
element 184, such as a balloon portion 198. Marker 188 is made of a
radiopaque material, such as platinum, iridium, gold, tungsten,
stainless steel, silver, composite material, and the like, which
can be detected by an imaging device, such as radiographic,
fluoroscopic, magnetic, sonographic device, and the like. Marker
188 is embedded within elongated member 182 at the activation site
of medical operational element 184, such as balloon portion 198.
Alternatively, marker 188 is located on outer wall 196 (i.e., outer
wall 196 is coated with marker 188).
Wiring 190 is wound around outer wall 196 at a pitch P.sub.2. For
this purpose, spiral grooves (not shown) can be formed on outer
wall 196, by a laser, mechanical engraving, chemical etching,
molding; injection; and extrusion, and the like, and wiring 190 is
then placed in the spiral grooves. Electromagnetic field detector
186 and wiring 190 are coated with a protective coating, in order
to provide electrical insulation and mechanical protection to
electromagnetic field detector 186 and to wiring 190 and
mechanically couple electromagnetic field detector 186 and wiring
190 to outer wall 196. Alternatively, electromagnetic field
detector 186 and wiring 190 are enclosed by a heat-shrinkable
material. Two ends (not shown) of electromagnetic field detector
186 are coupled with two distal ends (not shown) of wiring 190. Two
proximal ends (not shown) of wiring 190 are coupled with an MPS
similar to MPS 106 (FIG. 1A). Further alternatively, the wiring is
coupled to the outer wall of the elongated member, along a
substantially straight line (not shown). Alternatively, the wiring
is wound around the outer wall of the elongated member, at either a
constant pitch or a variable pitch along the length of the
elongated member. Further alternatively, at least one portion of
the wiring is substantially straight and at least another portion
is spiral.
Reference is now made to FIG. 4, which is a schematic illustration
of a lateral cross section of the wiring of a system for
determining position and orientation, such as shown in FIG. 1A, in
a twisted pair formation, generally referenced 200, constructed and
operative in accordance with another embodiment of the disclosed
technique. It is noted that the cross sectional proportions of the
different elements in FIG. 4 and all other Figures accompanying
this disclosure are not intended to illustrate the actual
dimensions or proportions and are exaggerated for the sake of
clarity. Wiring 200 includes electrical conductors 202 and 204,
electrical insulations 206, 208 and 212 and an electrical shielding
214. Electrical shielding 214 is a shielding layer similar to the
shielding of the electromagnetic field detector described above,
and provides electrical shielding to electrical conductors 202 and
204. Alternatively, electrical shielding 214 can be a fluid layer
which blocks electromagnetic waves in predetermined frequency
ranges. Further alternatively, a circumferential fluid lumen
similar to circumferential fluid lumen 140 (FIG. 1B), can function
as an electrical shielding for the wiring, or an electromagnetic
field detector similar to electrical field detector 114. Further
alternatively, each of electrical conductors 202 and 204 can be
hollow, wherein the hollow space is filled with a fluid. This fluid
can be employed for transmitting signals or for other medical
intervention purposes.
Electrical conductors 202 and 204 are enclosed within electrical
insulations 206 and 208, respectively. Distal ends (not shown) of
electrical conductors 202 and 204 are coupled with two ends (not
shown) of an electromagnetic field detector (not shown), similar to
electromagnetic field detector 114 (FIG. 1C). Proximal ends (not
shown) of electrical conductors 202 and 204 are coupled with an MPS
(not shown) similar to MPS 106 (FIG. 1A). Electrical conductors 202
and 204 together with electrical insulations 206 and 208, are
twisted together between the coupling to the electromagnetic field
detector and the coupling to the MPS. Thus, electrical conductors
202 and 204 together with electrical insulations 206 and 208, form
a twisted pair (not shown). Electrical shielding 214 encloses
electrical conductors 202 and 204 and electrical insulations 206
and 208. Electrical insulation 212 encloses electrical conductors
202 and 204, electrical insulations 206 and 208 and electrical
shielding 214.
Reference is now made to FIG. 5, which is a schematic illustration
of a lateral cross section of the wiring of a system for
determining position and orientation, such as shown in FIG. 1A, in
a coaxial formation, generally referenced 240, constructed and
operative in accordance with a further embodiment of the disclosed
technique. Wiring 240 includes electrical conductors 242 and 244
and electrical insulations 246 and 248. Electrical insulation 246
encloses electrical conductor 242. Electrical conductor 244 has a
substantially annular cross section and thus, encompasses
electrical conductor 242 and electrical insulation 246. Electrical
insulation 248 encompasses electrical conductors 242 and 244 and
electrical insulation 246. Distal ends (not shown) of electrical
conductors 242 and 244 are coupled with two ends (not shown) of an
electromagnetic field detector (not shown), similar to
electromagnetic field detector 114 (FIG. 1C). Proximal ends (not
shown) of electrical conductors 242 and 244 are coupled with an MPS
(not shown) similar to MPS 106 (FIG. 1A). Thus, electrical
conductors 242 and 244 together with electrical insulations 246 and
248, form a coaxial cable.
Reference is now made to FIG. 6, which is a schematic illustration
of a lateral cross section of the wiring of a system for
determining position and orientation, such as shown in FIG. 1A, in
a triaxial formation, generally referenced 270, constructed and
operative in accordance with another embodiment of the disclosed
technique. Wiring 270 includes electrical conductors 272 and 274,
electrical shielding 276 and electrical insulations 278, 280 and
282. Electrical shielding 276 is made of a conductive material,
which operates as a Faraday cage and provides electrical shielding
to electrical conductors 272 and 274.
Electrical insulation 278 encompasses electrical conductor 272.
Electrical conductor 274 has a substantially annular cross section
and thus, encompasses electrical conductor 272 and electrical
insulation 278. Electrical insulation 280 encompasses electrical
conductors 272 and 274 and electrical insulation 278.
Electrical shielding 276 encompasses electrical conductors 272 and
274 and electrical insulations 278 and 280. Electrical insulation
282 encompasses electrical conductors 272 and 274, electrical
insulations 278 and 280 and electrical shielding 276. Distal ends
(not shown) of electrical conductors 272 and 274 are coupled with
two ends (not shown) of an electromagnetic field detector (not
shown), similar to electromagnetic field detector 114 (FIG. 1C).
Proximal ends (not shown) of electrical conductors 272 and 274 are
coupled with an MPS (not shown) similar to MPS 106 (FIG. 1A). Thus,
electrical conductors 272 and 274 together with electrical
insulations 278, 280 and 282 and electrical shielding 276, form a
triaxial cable.
Reference is now made to FIGS. 7A and 7B. FIG. 7A is a schematic
illustration of a longitudinal cross section of the distal end of
the medical catheter of a system for determining position and
orientation, such as shown in FIG. 1A, generally referenced 300,
constructed and operative in accordance with a further embodiment
of the disclosed technique. FIG. 7B is a lateral cross section of
the medical catheter of FIG. 7A.
Medical catheter 300 includes an elongated member 302, an
electromagnetic field detector 304, electrical conductors 306 and
308 and a medical operational element 310. Elongated member 302 and
electromagnetic field detector 304 are similar to elongated member
108 (FIG. 1A) and electromagnetic field detector 114 (FIG. 1C),
respectively. In the example set forth in FIG. 7A, medical catheter
300 is a balloon-stent type catheter. Therefore, medical
operational element 310 includes a tube portion 312, a balloon
portion 314 and a stent 316. Tube portion 312 and balloon portion
314 are similar to tube portion 118 (FIG. 1C) and balloon portion
120, respectively. Tube portion 312 is coupled with a pressurized
fluid source (not shown), via a fluid lumen 318. A guidewire 320
can be passed through a guidewire lumen 322 within elongated member
302.
Electromagnetic field detector 304 is embedded within elongated
member 302, in a manner similar to the one described herein above
in connection with electromagnetic field detector 114 (FIG. 1C).
Distal ends (not shown) of electrical conductors 306 and 308 are
coupled with two ends (not shown) of electromagnetic field detector
304. Proximal ends (not shown) of electrical conductors 306 and 308
are coupled with an MPS (not shown), similar to MPS 106 (FIG.
1A).
Each of electrical conductors 306 and 308 can be encompassed within
an electrical insulation (not shown). Alternatively, each of
electrical conductors 306 and 308 can be encompassed within an
electrical shielding (not shown). Further alternatively, an
electrical shielding can encompass each of electrical conductors
306 and 308 and the respective electrical insulation.
Alternatively, an electrical insulation can encompass each of
electrical conductors 306 and 308 and the respective electrical
shielding.
Electrical conductors 306 and 308 are substantially located on the
same diametrical line of elongated member 302 and equally spaced
from the center of elongated member 302. In other words, electrical
conductor 306 is embedded within elongated member 302 along a first
path and electrical conductor 308 is embedded within elongated
member 302 along a second path. These first and second paths
substantially lie on a plane, whereby the plane substantially
passes through the longitudinal axis of elongated member 302. It is
noted that electrical conductors 306 and 308 can modify the
mechanical properties of elongated member 302, as described herein
above in connection with wiring 136 (FIG. 1C).
Stent 316 is an expandable type of stent as known in the art, such
as a wire mesh, a cylinder which includes a longitudinal cut, and
the like. A fluid flowing from the pressurized fluid source to tube
portion 312, causes balloon portion 314 to expand and the expansion
of balloon portion 314 causes stent 316 to expand.
Reference is now made to FIG. 8, which is a schematic illustration
of a lateral cross section of the distal end of the medical
catheter of a system for determining position and orientation, such
as shown in FIG. 1A, generally referenced 350, constructed and
operative in accordance with another embodiment of the disclosed
technique. Medical catheter 350 includes an elongated member 352,
electrical conductors 354 and 356 and a support element 358. A
guidewire 360 passes through a guidewire lumen 362 within elongated
member 352.
Each of electrical conductors 354 and 356 is similar to electrical
conductors 306 and 308, as described herein above in connection
with FIG. 7A. Support element 358 can be made of a material whose
physical properties are substantially similar to those of either
one of electrical conductors 354 or 356, but support element 358
can be made of other materials or have other properties. Electrical
conductors 354 and 356 and support element 358 are located equally
apart on a circle (not shown), which is substantially concentric
with the longitudinal axis of elongated member 352 (i.e., on radial
lines whose angle there between is approximately 120 degrees).
In this manner, electrical conductors 354 and 356 and support
element 358, modify the mechanical properties of elongated member
352, as described herein above in connection with wiring 136 (FIG.
1C). Analogously, any number of electrical conductors and support
elements can be distributed in the lateral cross section of the
elongated member, according to the desired mechanical properties of
the elongated member.
Reference is now made to FIG. 9, which is a schematic illustration
of a longitudinal cross section of the distal end of the medical
catheter of a system for determining position and orientation, such
as shown in FIG. 1A, generally referenced 410, constructed and
operative in accordance with a further embodiment of the disclosed
technique. Medical catheter 410 includes an elongated member 412,
an electromagnetic field detector 414, a PCB 416, a wiring 418 and
a medical operational element 420. Medical catheter 410 is a stent
type catheter Hence, medical operational element 420 includes a
stent 422 and a sleeve 424. A guidewire 426 can pass within a
guidewire lumen 428, within elongated member 412.
Elongated member 412, electromagnetic field detector 414, PCB 416
and wiring 418 are similar to elongated member 108 (FIG. 1A),
electromagnetic field detector 114, PCB 138 and wiring 136,
respectively, as described herein above in connection with FIG. 1C.
Electromagnetic field detector 414, PCB 416 and wiring 418 are
embedded within elongated member 412, in a manner similar to one
described herein above in connection with FIG. 1C. Distal ends (not
shown) of wiring 418 are coupled with two ends (not shown) of
electromagnetic field detector 414, via PCB 416. Proximal ends (not
shown) of wiring 418 are coupled with an MPS similar to MPS 106
(FIG. 1A).
Stent 422 is a spring type stent (i.e., self expandable stent) as
known in the art, which tends to expand, if no restraint is imposed
thereon. During assembly of medical operational element 420 on
elongated member 412, stent 422 is passed over an outer wall 430 of
elongated member 412 together with restraining sleeve 424, such
that sleeve 424 keeps stent 422 in a compressed state. In order to
activate medical operational element 420, sleeve 424 is pulled in a
direction designated by arrows 432, wherein stent 422 expands and
leaves outer wall 430.
Alternatively, stent 422 is made of a shape memory alloy (SMA),
such as nickel-titanium (nitinol), and the like, and sleeve 424 is
disposed of. The SMA stent is constructed such that when the
metallurgical structure of the SMA stent changes from a first phase
(e.g., Martensite) to a second phase (e.g., Austenite), the SMA
stent expands.
Reference is now made to FIG. 10, which is a schematic illustration
of a longitudinal cross section of the distal end of the medical
catheter of a system for determining position and orientation, such
as shown in FIG. 1A, generally referenced 450, constructed and
operative in accordance with another embodiment of the disclosed
technique. Medical catheter 450 includes an elongated member 452,
an electromagnetic field detector 454, a wiring 456 and an optical
fiber 458. Elongated member 452 and electromagnetic field detector
454 are similar to elongated member 108 (FIG. 1A) and
electromagnetic field detector 114 (FIG. 1C), respectively, as
described herein above. Wiring 456 is similar to either wiring 136
(FIG. 1C) or wiring 142 (FIG. 1D), as described herein above.
Electromagnetic field detector 454 and wiring 456 are embedded
within elongated member 452, in a manner similar to the one
described herein above in connection with FIG. 1C. A guidewire 460
can pass through a guidewire lumen 462, within elongated member
452.
Optical fiber 458 is embedded within elongated member 452. A distal
end 464 of optical fiber 458 is located at a distal end 466 of
elongated member 452. Distal end 464 can point either toward the
front of distal end 466, or toward a side (not shown) of distal end
466. A proximal end (not shown) of optical fiber 458 is coupled to
a laser (not shown). When the laser is activated, optical fiber 458
ablates a tissue (not shown), which is located in the vicinity of
distal end 466.
Reference is now made to FIG. 11, which is a schematic illustration
of a longitudinal cross section of the distal end of a medical
catheter of the rapid-exchange type, generally referenced 490,
constructed and operative in accordance with a further embodiment
of the disclosed technique. Rapid-exchange catheter is also known
in the art as Single Operator Exchange (SOE). Medical catheter 490
includes an elongated member 492, an electromagnetic field detector
494, a wiring 496 and a medical operational element 498. Medical
catheter 490 is a balloon type catheter. Therefore, medical
operational element 498 includes a tube portion 500 and a balloon
portion 502.
Wiring 496 is similar to either wiring 136 (FIG. 1C) or wiring 142
(FIG. 1D), as described herein above. Electromagnetic field
detector 494 is made of an electrical conductor (not shown), wound
around a core 504. Core 504 is made of a material whose
permeability is substantially greater than that of the air. Hence,
core 504 can be made of a ferromagnetic material (e.g., ferrite,
iron, Mu-metal, superalloy, soft ferrite), and the like, as well as
a paramagnetic material. Electromagnetic field detector 494 is
embedded within elongated member 492. Wiring 496 is embedded within
elongated member 492 in a manner similar to the one described
herein above in connection with FIG. 1C. Distal ends (not shown) of
wiring 496 are coupled with two ends (not shown) of electromagnetic
field detector 494. Proximal ends (not shown) of wiring 496 are
coupled with an MPS, similar to MPS 106 (FIG. 1A). A distal end 506
of balloon portion 502 is coupled with a distal end 508 of
elongated member 492, in a manner similar to the one described
herein above, in connection with FIG. 1C.
Elongated member 492 includes a guidewire lumen 510, whose entrance
512 is located at distal end 508 and whose exit 514 is located at a
side portion 516 of elongated member 492. Side portion 516 is
located at a proximal end 518 of balloon portion 502.
Electromagnetic field detector 494 is located proximal to exit 514
(i.e., adjacent to proximal end 518). A concentric fluid lumen 520
formed between tube portion 500 and an outer wall 522 of elongated
member 492, is coupled with a pressurized fluid source similar to
the one described herein above, in connection with FIG. 1A.
A region of tube portion 500 in the vicinity of side portion 516 is
coupled with side portion 516, in order to prevent fluid
communication between guidewire lumen 510 and concentric fluid
lumen 520. Tube portion 500 is perforated at side portion 516, in
order to keep exit 514 open. In order to guide medical catheter 490
over a guidewire 524, the physician enters a proximal end 526 of
guidewire 524 through entrance 512, until proximal end 526 of
guidewire 524 passes through guidewire lumen 510 and exits
guidewire lumen 510 at exit 514. This mode of operation is known in
the art as "rapid-exchange".
It is noted that since a portion of elongated member 492 proximal
to exit 514 is solid, it is possible to incorporate core 504 with
electromagnetic field detector 494. Furthermore, since core 504 is
made of a ferromagnetic material, electromagnetic field detector
494 is more sensitive to the electromagnetic field generated by a
transmitter similar to transmitter 134 (FIG. 1A), than an
electromagnetic field detector similar to electromagnetic field
detector 114 (FIG. 1C).
Reference is now made to FIG. 12, which is a schematic illustration
of a longitudinal cross section of the distal end of a medical
catheter of the rapid-exchange type, generally referenced 550,
constructed and operative in accordance with another embodiment of
the disclosed technique. Medical catheter 550 includes an elongated
member 552, an electromagnetic field detector 554, a wiring 556 and
a medical operational element 558. Medical catheter 550 is a
balloon type catheter. Therefore, medical operational element 558
includes a tube portion 560 and a balloon portion 562. Medical
operational element 558 is similar to medical operational element
498 (FIG. 11), as described herein above. Medical operational
element 558 is constructed in a manner similar to the one described
herein above in connection with FIG. 11.
Elongated member 552 includes a guidewire lumen 564, whose entrance
566 is located at a distal end 568 of elongated member 552. An exit
570 of guidewire lumen 564 is located at a side portion 572 of
elongated member 552. Side portion 572 is located at a proximal end
574 of balloon portion 562.
Guidewire lumen 564 is similar to guidewire lumen 510 (FIG. 11), as
described herein above. Electromagnetic field detector 554 is
similar to electromagnetic field detector 114 (FIG. 1C), as
described herein above. Wiring 556 is similar to either wiring 136
(FIG. 1C) or wiring 142 (FIG. 1D), as described herein above.
Distal ends (not shown) of wiring 556 are coupled with two ends
(not shown) of electromagnetic field detector 554. Proximal ends
(not shown) of wiring 556 are coupled with an MPS, similar to MPS
106 (FIG. 1A).
Electromagnetic field detector 554 is embedded within elongated
member 552 as described herein above in connection with FIG. 1C,
such that guidewire lumen 564 passes through the winding of
electromagnetic field detector 554. Electromagnetic field detector
554 is embedded in such a location within elongated member 552,
that when balloon portion 562 expands, balloon portion 562
encompasses electromagnetic field detector 554.
The physician enters a proximal end 576 of a guidewire 578 into
guidewire lumen 564 through entrance 566, passes guidewire 578
through guidewire lumen 564 and pushes guidewire lumen 564 out
through exit 570. Medical catheter 550 operates in rapid-exchange
mode, while electromagnetic field detector 554 is located such that
balloon portion 562 encompasses electromagnetic field detector 554,
when balloon portion 562 expands. Thus, medical catheter 550 allows
the MPS to determine the location of medical operational element
558, more accurately than that of medical catheter 490 (FIG.
11).
Alternatively, the electromagnetic field detector is wound around
an outer wall 580 of elongated member 552. Further alternatively,
the electromagnetic field detector is located proximal to exit 570,
while the electromagnetic field detector is either embedded within
the elongated member or is wound around the outer wall of the
elongated member.
Reference is now made to FIG. 13, which is a schematic illustration
of a system for determining the relative positions and orientations
of a plurality of medical catheters, generally referenced 600,
constructed and operative in accordance with a further embodiment
of the disclosed technique. System 600 includes a plurality of
medical catheters 602 and 604, a plurality of guidewires 606 and
608 and an MPS 610. Each of medical catheters 602 and 604 is
similar to either medical catheter 102 (FIG. 1A), medical catheter
490 (FIG. 11) or medical catheter 550 (FIG. 12), as described
herein above. MPS 610 is similar to MPS 106 (FIG. 1A), as described
herein above.
Medical catheter 602 includes a medical operational element 612 and
an electromagnetic field detector 614. Medical catheter 604
includes a medical operational element 616 and an electromagnetic
field detector 618. Each of medical operational elements 612 and
616 is similar to medical operational element 112 (FIG. 1A), as
described herein above. If a guidewire lumen (not shown) within an
elongated member (not shown) of each of medical catheter 602 and
604, is similar to guidewire lumen 116 (FIG. 1C), then each of
electromagnetic field detectors 614 and 618 is similar to
electromagnetic field detector 114 (FIG. 1C) or electromagnetic
field detector 186 (FIG. 3), as described herein above. If the
guidewire lumen within the elongated member of each of medical
catheter 602 and 604, is similar to guidewire lumen 510 (FIG. 11),
then each of electromagnetic field detectors 614 and 618 is similar
to electromagnetic field detector 494, as described herein
above.
Electromagnetic field detectors 614 and 618 are coupled to MPS 610,
via wirings 620 and 622, respectively. Each of wirings 620 and 622
is similar to wiring 136 (FIG. 1C), as described herein above.
Medical catheters 602 and 604 are passed over guidewires 606 and
608, respectively, into lumens 624 and 626, respectively, of a
patient (not shown). Electromagnetic field detectors 614 and 618
detect the electromagnetic field generated by a transmitter (not
shown) of MPS 610 and provide MPS 610 respective signals, via
wirings 620 and 622, respectively. MPS 610 determines the position
and orientation of medical operational element 612 relative to
medical operational element 616, according to the signals received
from electromagnetic field detectors 614 and 618.
Reference is now made to FIG. 14, which is a schematic illustration
of a system for determining the position and orientation of a
guiding catheter, generally referenced 650, constructed and
operative in accordance with another embodiment of the disclosed
technique. System 650 includes a guiding catheter 652, a medical
catheter 654 and an MPS 656. Guiding catheter 652 includes an
electromagnetic field detector 658. Medical catheter 654 includes
an elongated member 660, an electromagnetic field detector 662 and
a medical operational element 664. Elongated member 660 includes a
guidewire lumen 666.
Guidewire lumen 666 is either similar to guidewire lumen 116 (FIG.
1C) or guidewire lumen 510 (FIG. 11), as described herein above.
Electromagnetic field detector 662 is similar to either
electromagnetic field detector 114 (FIG. 1C), electromagnetic field
detector 186 (FIG. 3), or electromagnetic field detector 494 (FIG.
11), according to the type of guidewire lumen 666. Medical
operational element 664 is similar to medical operational element
112 (FIG. 1C), as described herein above. Electromagnetic field
detector 662 is located at an activation site (not shown) of
medical operational element 664.
Electromagnetic field detector 658 is made of an electric conductor
wound around an outer wall 668 of guiding catheter 652.
Alternatively, the electromagnetic field detector is located within
a wall of the guiding catheter. Electromagnetic field detector 658
is coupled with MPS 656 via a wiring 670. Wiring 670 is wound
around outer wall 668. Alternatively, wiring 670 lies in a
substantially straight line on outer wall 668. Electromagnetic
field detector 658 and wiring 670 are coated with a protective
layer, such as an adhesive, and the like. The protective layer
provides mechanical and electrical protection to electromagnetic
field detector 658 and to wiring 670. The protective layer is
coated with a lubricant to facilitate the travel of guiding
catheter 652 within a lumen (not shown) of a patient (not
shown).
Electromagnetic field detector 662 is coupled with MPS 656, via a
wiring 672. Wiring 672 is similar to either wiring 136 (FIG. 1C) or
wiring 142 (FIG. 1D), as described herein above. Medical catheter
654 is located within guiding catheter 652. A guidewire 674 passes
through guidewire lumen 666.
Electromagnetic field detector 658 detects an electromagnetic field
generated by a transmitter (not shown) of MPS 656 and provides a
respective signal to MPS 656, via wiring 670. Electromagnetic field
detector 662 detects an electromagnetic field generated by the
transmitter and provides a respective signal to MPS 656, via wiring
672. MPS 656 determines the position and orientation of
electromagnetic field detector 658 in a reference coordinate
system, according to the signal received from electromagnetic field
detector 658. If electromagnetic field detector 658 is located at a
distal end 676 of guiding catheter 652, then MPS 656 determines the
position and orientation of distal end 676 in the reference
coordinate system. Alternatively, MPS 656 determines the position
and orientation of electromagnetic field detector 662 (i.e., the
activation site of medical operational element 664), relative to
electromagnetic field detector 658 (i.e., distal end 676),
according to signals received from electromagnetic field detectors
658 and 662.
Reference is now made to FIG. 15, which is a schematic illustration
of a method for operating the system of FIG. 1A, operative in
accordance with a further embodiment of the disclosed technique. In
procedure 700, a medical catheter is advanced to the desired
location within an organic lumen.
Prior to procedure 700, a guiding catheter can be advanced to an
approximate location proximal to a desired location within an
organic lumen. Additionally, the guidewire can be advanced within
the guiding catheter to the desired location, past a guiding
catheter distal end. With reference to FIG. 1A, in case a guidewire
was previously inserted through the guiding catheter, the physician
inserts the proximal end of guidewire 104 into distal end 144 of
medical catheter 102 and advances medical catheter 102 to the
desired location within a lumen of a patient, over guidewire 104.
At this stage, the physician can view an image of guidewire 104 on
an imaging device, such as radiographic, fluoroscopic, magnetic,
sonographic device, and the like. In case no guidewire was
previously employed, the physician advances the medical catheter to
the desired location, through the guiding catheter. Optionally,
with reference to FIG. 14, electromagnetic field detector 658 is
mounted at distal end 676 of guiding catheter 652, thereby allowing
detection of the position and orientation of guiding catheter 652
without employing X-ray or fluoroscopy, and with the precision of
MPS.
In procedure 702, an electromagnetic field detector located at a
medical catheter distal end, is coupled with an MPS by a wiring.
According to a preferable embodiment, the wiring affects the
mechanical properties of the medical catheter, such as the
pushability and trackability of the medical catheter through the
organic lumen (when the medical catheter extends beyond the guiding
catheter distal end). With reference to FIGS. 1A and 1C,
electromagnetic field detector 114 which is located at distal end
114 of medical catheter 102, is coupled with MPS 106, via wiring
136. Since wiring 136 is spirally embedded within elongated member
108, the mechanical properties of elongated member 108, such as
pushability and trackability of elongated member 108 through the
lumen, are modified. It is noted that wiring 136 can be embedded
within elongated member 108 in a substantially straight line, or a
combination of spiral and straight sections, wherein wiring 136
still modifies the mechanical properties of elongated member
108.
In procedure 704, an electromagnetic field is generated by the MPS.
With reference to FIG. 1A, transmitter 134 generates an
electromagnetic field. In procedure 706, the generated
electromagnetic field is detected by the electromagnetic field
detector.
In procedure 708, a signal respective of the detected
electromagnetic field is transmitted to the MPS, via the wiring.
With reference to FIG. 1A, electromagnetic field detector 114
detects the electromagnetic field generated by transmitter 134 and
electromagnetic field detector 114 transmits a signal respective of
the detected electromagnetic field, to detector interface 124, via
wiring 136.
In procedure 710, the position and orientation of the medical
catheter distal end is determined by the MPS, according to the
transmitted signal. With reference to FIG. 1A, processor 126
receives from detector interface 124, the signal which was
transmitted to detector interface 124 by electromagnetic field
detector 114 and processor 126 determines the position and
orientation of distal end 144 of medical catheter 102, according to
the transmitted signal.
In procedure 712, a medical operation is performed by activating a
medical operational element located at the medical catheter distal
end. With reference to FIGS. 1A and 1B, the physician inflates
balloon portion 120 by introducing a fluid from a pressurized fluid
source, into tube portion 118.
It will be appreciated by persons skilled in the art that the
disclosed technique is not limited to what has been particularly
shown and described hereinabove. Rather the scope of the disclosed
technique is defined only by the claims, which follow.
* * * * *
References